code: def service_available(self):
      cur_time = int(time.time())
      if (
          self._valid_time is None
          or cur_time - self._valid_time > SERVICE_LIFE
      ):
          self._service_available = self._dana_cli.service_available()
          self._valid_time = cur_time
      return self._service_available
  
file_path: mace/tools/dana/dana_util.py
imports: from dana.dana_cli import DanaCli
  from dana.dana_cli import DanaTrend
  import os
  import re
  import sh
  import time
label_desc: Use image node_id 12 for calling the DanaUtil obj's underlying member method code with example usage: obj.service_available() and returns: self